diff --git a/libcxx/cmake/Modules/HandleLibcxxFlags.cmake b/libcxx/cmake/Modules/HandleLibcxxFlags.cmake
--- a/libcxx/cmake/Modules/HandleLibcxxFlags.cmake
+++ b/libcxx/cmake/Modules/HandleLibcxxFlags.cmake
@@ -36,31 +36,6 @@
   endforeach()
 endmacro()
 
-# Add a list of flags to 'LIBCXX_COMPILE_FLAGS'.
-macro(add_compile_flags)
-  foreach(f ${ARGN})
-    list(APPEND LIBCXX_COMPILE_FLAGS ${f})
-  endforeach()
-endmacro()
-
-# If 'condition' is true then add the specified list of flags to
-# 'LIBCXX_COMPILE_FLAGS'
-macro(add_compile_flags_if condition)
-  if (${condition})
-    add_compile_flags(${ARGN})
-  endif()
-endmacro()
-
-# For each specified flag, add that flag to 'LIBCXX_COMPILE_FLAGS' if the
-# flag is supported by the C++ compiler.
-macro(add_compile_flags_if_supported)
-  foreach(flag ${ARGN})
-      mangle_name("${flag}" flagname)
-      check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
-      add_compile_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
-  endforeach()
-endmacro()
-
 # Add a list of flags to 'LIBCXX_LINK_FLAGS'.
 macro(add_link_flags)
   foreach(f ${ARGN})
@@ -68,24 +43,6 @@
   endforeach()
 endmacro()
 
-# If 'condition' is true then add the specified list of flags to
-# 'LIBCXX_LINK_FLAGS'
-macro(add_link_flags_if condition)
-  if (${condition})
-    add_link_flags(${ARGN})
-  endif()
-endmacro()
-
-# For each specified flag, add that flag to 'LIBCXX_LINK_FLAGS' if the
-# flag is supported by the C++ compiler.
-macro(add_link_flags_if_supported)
-  foreach(flag ${ARGN})
-    mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
-    add_link_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
-  endforeach()
-endmacro()
-
 # Add a list of libraries or link flags to 'LIBCXX_LIBRARIES'.
 macro(add_library_flags)
   foreach(lib ${ARGN})
diff --git a/libunwind/cmake/Modules/HandleLibunwindFlags.cmake b/libunwind/cmake/Modules/HandleLibunwindFlags.cmake
--- a/libunwind/cmake/Modules/HandleLibunwindFlags.cmake
+++ b/libunwind/cmake/Modules/HandleLibunwindFlags.cmake
@@ -10,33 +10,6 @@
 
 unset(add_flag_if_supported)
 
-# Add a specified list of flags to both 'LIBUNWIND_COMPILE_FLAGS' and
-# 'LIBUNWIND_LINK_FLAGS'.
-macro(add_flags)
-  foreach(value ${ARGN})
-    list(APPEND LIBUNWIND_COMPILE_FLAGS ${value})
-    list(APPEND LIBUNWIND_LINK_FLAGS ${value})
-  endforeach()
-endmacro()
-
-# If the specified 'condition' is true then add a list of flags to both
-# 'LIBUNWIND_COMPILE_FLAGS' and 'LIBUNWIND_LINK_FLAGS'.
-macro(add_flags_if condition)
-  if (${condition})
-    add_flags(${ARGN})
-  endif()
-endmacro()
-
-# Add each flag in the list to LIBUNWIND_COMPILE_FLAGS and LIBUNWIND_LINK_FLAGS
-# if that flag is supported by the current compiler.
-macro(add_flags_if_supported)
-  foreach(flag ${ARGN})
-      mangle_name("${flag}" flagname)
-      check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
-      add_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
-  endforeach()
-endmacro()
-
 # Add a list of flags to 'LIBUNWIND_COMPILE_FLAGS'.
 macro(add_compile_flags)
   foreach(f ${ARGN})
@@ -77,16 +50,6 @@
   endif()
 endmacro()
 
-# For each specified flag, add that flag to 'LIBUNWIND_C_FLAGS' if the
-# flag is supported by the C compiler.
-macro(add_c_compile_flags_if_supported)
-  foreach(flag ${ARGN})
-      mangle_name("${flag}" flagname)
-      check_c_compiler_flag("${flag}" "C_SUPPORTS_${flagname}_FLAG")
-      add_c_flags_if(C_SUPPORTS_${flagname}_FLAG ${flag})
-  endforeach()
-endmacro()
-
 # Add a list of flags to 'LIBUNWIND_CXX_FLAGS'.
 macro(add_cxx_flags)
   foreach(f ${ARGN})